downpipe

[RobG]

i just installed a 3inch downpipe on my 97 eclipse gsx..i took the cat off..it slowed the car down alotttt...could it have something to do with the ecu?

 

[hubz91talontsi]

Its a 97...which means you took out an o2 sensor correct...? So your CEL is on and your down an o2 sensor im guessing your ecu is a little confused.

 

[red_devil]

Its a 97...which means you took out an o2 sensor correct...? So your CEL is on and your down an o2 sensor im guessing your ecu is a little confused.

Nope the cat delete downpipes do not remove the 02 sensor, they just replace the cat. Doing this would not effect the rear o2 sensor since it does not effect fuel trims. The rear o2 is only there to tell you the cat is working or not, and most of the time they do not even know that your no longer running a cat.

You may have an exhaust leak of some kid or are hitting fuel cut due to the increased flow.

 

[the_mork]

Are you running the downpipe to the stock exhaust? If so then when the exhaust hits the smaller piping it could be backing up and choking off flow, if not then consider that you may be hitting a higher peak boost which is causing knock and pulling timing.

What are your other mods? If you could put them in your profile that would be nice.

 

[RobG]

Are you running the downpipe to the stock exhaust? If so then when the exhaust hits the smaller piping it could be backing up and choking off flow, if not then consider that you may be hitting a higher peak boost which is causing knock and pulling timing.

What are your other mods? If you could put them in your profile that would be nice.

it has a 3inch exhuast all the way back..theres a bov..walbro 255 fuel pump..manual boost controller..upper ic piping

 

[the_mork]

What boost are you running now? Where was it before you changed the downpipe?

Are you running an afpr with that fuel pump?

Try doing a boost leak test, its possible that this install and your problems are actually unrelated.

 

[RobG]

boost i was running was 14lbs i put it back down to the stock 9lbs and it did the same thing no i dont have a afpr

What boost are you running now? Where was it before you changed the downpipe?

Are you running an afpr with that fuel pump?

Try doing a boost leak test, its possible that this install and your problems are actually unrelated.

 

[romeen]

Did you do any other work or remove/replace anything else when you installed the DP?

 

[red_devil]

boost i was running was 14lbs i put it back down to the stock 9lbs and it did the same thing no i dont have a afpr

You need to get an fpr with a 255 pump as it overloads the stock one.

 

[RobG]

Did you do any other work or remove/replace anything else when you installed the DP?

took the bumper off the turbo intake the headlights and thats all everythings hooked up unless im forgettin something but i dont think so iv'e take it apart many times

 

[romeen]

I can't think of any reason why switching to a larger DP would cause a loss of power. It shouldn't affect the ECU at all unless you disconnected the battery while doing the work. If you did then the ECU was reset and has to "relearn" your driving style. But that shouldn't cause the kind of power loss that you are describing.

If you messed with any part of the intake post-turbo then it could be a boost leak. A boost leak test is ALWAYS a good idea to do as leaks tend to pop up randomly and can really affect performance.

I doubt that it's related directly to the DP. Double check all the other areas where you did some work paying particular attention to the intake tract. Look for a CEL. Make sure you don't have any pre-turbo exhaust leaks. It's probably something simple.

 

[RobG]

I can't think of any reason why switching to a larger DP would cause a loss of power. It shouldn't affect the ECU at all unless you disconnected the battery while doing the work. If you did then the ECU was reset and has to "relearn" your driving style. But that shouldn't cause the kind of power loss that you are describing.

If you messed with any part of the intake post-turbo then it could be a boost leak. A boost leak test is ALWAYS a good idea to do as leaks tend to pop up randomly and can really affect performance.

I doubt that it's related directly to the DP. Double check all the other areas where you did some work paying particular attention to the intake tract. Look for a CEL. Make sure you don't have any pre-turbo exhaust leaks. It's probably something simple.

yeah...gunna put it back up on the lift and check it out tommorw..thanks for the help

 

[RobG]

yeah...gunna put it back up on the lift and check it out tommorw..thanks for the help

problem sloved...i unhooked the boost controller and hooked the line back up to the internal wastegate ran it and hooked it back up to the boost controller...maybe the boost controlled got confused? idk w/e it works now